Process for the production of black dyeings on cellulose fabrics



United States Patent Ofiice 3,301,629

Patented Jan. 31, 1967 3 301 629 w of suitable-assistants, for instance of cation-active after- PROCESS FOR THE PR()DUCTIN 0F BLACK treatment agents, during the diazotisation or the cou- DYEINGS 0N CELLULOSE FABRICS plying Operation, or Subsequent to up g- Bernhard Kramer, Cologne-Braunsfeld, and Gerd Henes, I11 accordance With the Choice Of the "c pl g m- Opladen, Germany, assignors to Farbenfabriken Bayer ponent selected for development, different colour shades Aktiengesellschaft,Leverkusen, Germany, acorporation of black are obtained. Thus, if development is for ina? g py 1 F d 0 t 9 S N 5 stance carried out with the aid of an alkaline solution o 'P 1e t of. 2,4-to1uylen diamine, a full brownish black colour Chums pnonty apphcatlon Germany 1963 is obtained, whereas development with an alkaline solu- 4 j i% i i 10 tion of ,B-naphthol produces a more bluish black colour.

v p 'Other suitable coupling components which may be ap- It has beenfound that fast deep black dyeings are plied in the form of their alkali metal salts or of their obtained'ori cellulose fabrics 'when a mixture of azo salts with hydracids are, for instance, m-phenylene dyestutfsof the composition -diamine, a naphthol, 1 phenyl-3-methyl-5-pyrazolone,

OOHa HO- and or their alkali ;-metalfsalts,optionally in the form of 'a resorcinol, m-hydroxy-aminobenzene, 2,3-hydroxynaph- 'mixture with other toning dyestufis, is diazotised on the 'thoic acid, N ethyl {3 naphthylamine, 4 chloro 1,3-

fibre and combined with coupling components free from diaminobenzene, phenol, N-ethyl-et-naphthylamine and sulphonic acid groups, 1-phenyl-5-pyrazolone-3-carboxylic acid ethyl ester.

i The dyestuffs to be employed according to the process The mixture proportions of the dyestuffs (I) and (II), are known polyazo dyestuffs bythe use of which-black 35, optionally in conjunction with other toning dyestuffs, may dyeings may be produced on cellulose fabrics, and in .vary within wide limits, for instance in the range 1:5 to particular on textile materials of native or regenerated 5:1, the preferred range being 1:2 to 2:1.

cellulose. Although the dyestufis are satisfactory in 're- The developed black dyeings are not subsequently spect of their fastness properties, they produce weak coppered. It is surprising that the dyeings nevertheless (empty) dyeings on staple rayon. on the other hand, 40 exhibit the same good fastness properties as dyeings with diazotisation black dyestufis are known for cellulose but mixtures of the dyestuffs (I) and (II) which had been their dyeings do not exhibit the necessary fastness propertreated with copper discharging agents, although on com ties. By the use of the mixture to be employed in acparison' with the latter they exhibit the advantage of givcordance with the process, it becomes possible to achieve ing a, considerably ,deeper coloration 0n rayon staple. deep bloomy black shades on cotton as well as on cel- The mixture may contain a proportion of about 1 to 35% lulose fibre without any reduction in the fastness level 0f the usual dyestuffs p y as toning 0f p y- -of the individual dyestulfs. L l in'g dyestuffs in' black'mixtures, such as p,p'-diaminodi- The diazotisation on the fibre of the mixtures to be phenylureazsalicyclic acid; 4'-amino-l-methylbenzene-Z- employed according to the process is carried out by the sulphonic amino 1 y y benzene, method known for diazotisation dyestuffs. In order to t1eated with phosgene; c-flcid'vl-naphthylamine'ecleve produce intensive full black shades, between 5 and 10% P Y acid- .of the dyestulf mixture is applied in practice on cotton 1,7- I-acid; salicyclic acid benzidine (o-chloraniline-S- and on cellulose fibre. Dyeings on skeins, cross wound sulphonic y t opp pp .bobbins and iec goods lead to results of the same p x of 2-amino-5-sulphobenzoic i oquality. phenyl) 3 methyl 5 pyrazolone l-amino-2-ethoxy- The process is carried out in detail in that the goods naphthalene-G-sulphonic acidphenyl-I-acid, salicyclic are padded with the mixture of the specified dyestuffs, p-nitraniline, reduced aminohydroquinone dimethyl optionally with the addition of other toning dyestulfs, etherl i' -acid condensation product of l-amin0-4-(4' for instance on a Foularding machine at an: elevated temamino-phenylamino)-anthraquinone 2 sulphonic acid perature, preferably a temperature of 50 to-75? C., and with the urethane from 4-amino-4'-hydroxy-3'carboxythat they are subsequently steamed, rinsed, and squeezed l,l'-'azobenzene; and nitroanthranilic acid phenyl-I- out. The fabric is then treated in a bath containing acid, reduced, treated with phosgene and coppered. the required amount of sodium nitrite. A further bath The results attained with the mixture to be employed treatment follows, where hydrochloride acid is applied according to the invention not only produce an advanat an elevated temperature so as to cause diazotisation. tage in dyeing in relation to the nearest comparable dye- It is subsequently rinsed in the cold and finally develstuffs, but in addition they are unexpected since it may oped at an elevated temperature in a bath containing a be seen from Colour Index, 2nd edition, volume II, page solution of the coupling component. When the devel- 2332 (Benzo Fast Black G=C.I. Direct Black 19) and oped dyeing has been rinsed again, it can be Washed page 2358 (Benzo Fast Copper Black GL=C.I. Direct or'after-treated with soap. The wet fast'ness proper Black that both the individual dyestuffs are said to ties can be improved in known manner by the addition be unsuitable for diazotisation on the fibre and subse- 3 quent development.

The following examples, wherein the term parts denotes parts by Weight, are given for the purpose of illustrating the invention.

Example 1 A 5 to 7% dyeing is prepared on cotton or staple rayon in accordance with the usual method of dyeing with the addition of 10 to 40% of Duisburg sodium sulphate, using a mixture of:

(a) 40 parts of dyestuif (1) (concentration 50:100) and (b) 30 parts of dyestuif (II) (concentration 351100), or

with a mixture of (c) 45 parts of dyestuff (I) (concentration 40:100) and (d) 35 parts of dyestuff (II) (concentration 25 :100) and (e) 25 parts of the azo dyestuff l-amino-4-nitrobenzene- 2 carboxylic acid-+2-phenylamino-5-hydroxy-naphthalene-7-sulphonic acid, reduced at the nitro groups and treated with phosgene and coppered (concentration 80:100) and (f) parts of the azo dyestufr' which is obtained by treatment of approximately equimolar amounts of 4- amino 4-hydroxy-3-carboxy-1,1'-azobenzene and 1- amino 4-(4' aminophenylamino)-anthraquinone-2- sulphonic acid with phosgene (concentration 70:100),

dyeing being carried out at about 80 to 95 C. during 1 to1.5 hours.

The resultant dyeings are thoroughly rinsed and treated for minutes in a fresh cold aqueous bath containing 0.75 to 1.5 g./l. of sodium nitrite and 2.5 to 4 ml. of hydrochloric acid (20 B.) or, if iron vessels are employed, 1.5 to 2.5 ml. of sulphuric acid (66 B.) so that they are diazotised. It is thereafter thoroughly rinsed again and the dyeing is at once developed in a fresh aqueous bath containing a solution of 0.8 to 1.5 g./l. of [3- naphthol or 0.5 to 1 g./l. of 2,4-toluylene diamine. The treatment in the developing liquid requires about 20 to 30 minutes and is carried out at room temperature. A full black with excellent fastness properties is obtained.

The mixtures with other accompanying or toning dyestuffs mentioned in the description may also be employed with the same good results in place of the dyestufl? mixtures applied in this example. The proportions in the mixture may vary, depending on the character of the desired shade of black.

Other developing agents, such as the salts mentioned in the description, may also be employed in place of the developing agents ,B-naphthol and 2,4-toluylene-diamine employed in this example.

Dyestuff mixtures are generally adjusted to the desired concentration with the aid of assistants such as sodium carbonate, dextrine, trisodium phosphate, sodium sulphate and the like. The two dyestufl? mixtures mentioned under (a) to (f) may for instance be diluted with 10 parts of sodium carbonate and 7 parts of dextrine and 16 parts of trisodium phosphate.

4- Example 2 A fabric of cotton or staple rayon is foularded by the usual method at a residual moisture content of 80% and a temperature of C., 20 g. of a dyestuff is employed which in this case consists of the following individual components:

30 parts of dyestuff (I) (concentration 20:

15 parts of dyest-uif (f) from Example 1,

33 parts of dyestuff II (concentration 30: 100), and

22 parts of dyestuff (e) from Example 1.

The dyestuif mixture is diluted with 9.5 parts of sodium carbonate, 7 parts of dextrine and 16 parts of trisodium phosphate.

The fabric is sequentially steamed at 103 C., and thereafter the goods are passed through a rinsing box filled with water, squeezed out and treated in two further vessels each of which contains 20 g./l. of sodium nitrite and is kept at a temperature of 50 C. A subsequent air passage lasting for about 15 seconds serves for the purpose of improving the penetration of the sodium nitrite into the fibre. After the air passage, the goods are passed into the next vessel which contains 50 cc./l. of hydrochloric acid and is warmed to 40 C. The above described intermediate foularding operation is necessary if it is intended to prevent too much sodium nitrite from being carried over into the bath of hydrochloric acid. Cold rinsing is carried out in the fourth and fifth vessels, and in the sixth vessel the goods pass through a bath at a temperature of 40 C. which is filled with 10 g./l. of toluylene diamine (pH 8 to 8.5), the developing agent. Another air passage for about 15 seconds follows in order to improve the coupling of the dyestuiT. It is then rinsed in the seventh and eighth vessel, or soa-ped with 1 to 2 g./l. of the sodium salt of a parafiin-sulphonic acid at 40-60 C. The sodium nitrite, hydrochloric acid and developer baths have to be replenished by continuous further additions.

In the description and the examples the arrows or are to indicate the coupling direction of the diazo compound of the diazotizable amine upon the given coupling component; alk means that coupling takes place under alkaline conditions and thus occupies the o-position relative to the OH group of the coupling component. The double arrow indicates coupling of 1 mol of the tetrazo compound with two mols of the coupling component. I-acid is 2-amino-5-hydroxynaphthalene-7-sulfonic acid, 'y-acid is 2-amino-8-hydroxynaphthalene-6-sulfonic acid, phenyl-I-acid is 2-phenylamino-5-hydroxynaphthalene-7-sulfonic acid, Cleve acid-1,7 is l-amino-naphthalene-7-sulfonic acid, and C-acid is 2-amino-naphthalene- 4,8-disulfonic acid.

We claim:

1. Process for the production of black dyeings on cellulosefabrics, which comprises applying a mixture of azo dyestuffs which in the free acid state are of the formula diazotizing them on the fibre and combining with coupling components free of sulfonic acid groups.

2. Process according to claim 1 wherein the. dyestuffs are applied onto the cellulosic fabrics in admixture with other toning dyes.

3. Process according to claim 1, characterised in that a proportion of about 1:2 to 2:1 of said dyestulfs is present in the mixture.

4. Cellulose fabrics dyed in accordance with the process of claim 1.

References Cited by the Examiner UNITED STATES PATENTS 6 OTHER REFERENCES Cockett et a1.: Dyeing of Cellulosic Fibers, p. 177, 1961, Academic Press, New York.

Colour Index, 1956 ed., vol. 2, pp. 2332 and 2358, entries C.I. Direct Black 19 and CI. Direct Black 95.

Lubs: The Chemistry of Synthetic Dyes and Pigments, 1955, pp. 122, 123, 132 and 133, Publ. by Reinhold Publ. Corp., New York.

Zollinger: Amer. Dyestuif Reporter, Mar. 7, 1960, pp. 31 and 32.

NORMAN G. TORCHIN, Primary Examiner.

T. J. HERBERT, Assistant Examiner. 

1. PROCESS FOR THE PRODUCTION OF BLACK DYEINGS ON CELLU LOSE FABRICS, WHICH COMPRISES APPLYING A MIXTURE OF AZO DYESTUFFS WHICH IN THE FREE ACID STATE ARE OF THE FORMULA 